Long-term Safety and Efficacy of Reslizumab in Patients with Eosinophilic Asthma

Biological treatments for severe asthma

Severe asthma patients comprise about 3% to 13% of all asthma patients, but they have higher hospital utilization rates and higher medical costs than those of nonsevere asthma patients. Treatment methods for severe asthma patients are still lacking; however, the recent development of biologics is expected to have a positive effect. The biological therapies developed so far are mainly aimed at treating asthma patients with type 2 inflammation. These biologics have been found to reduce symptoms of asthma, improve lung function, reduce the use of oral corticosteroids, and improve quality of life of patients. This article reviews the mechanism of action and indications for approved biologics and discusses what should be considered when choosing biologics.

Clinical Development of Mepolizumab for the Treatment of Severe Eosinophilic Asthma: On the Path to Personalized Medicine

The development of mepolizumab, an anti-IL-5 monoclonal antibody for the treatment of severe eosinophilic asthma, is an example of a clinical development program that evolved over time based on sound, basic scientific principles. Initial clinical data on the effects of mepolizumab on lung function in a general asthmatic population were disappointing. However, it became clear that mepolizumab may be more effective against other clinical endpoints, particularly asthma exacerbations, in patients with more severe disease. Furthermore, a developing understanding of asthma disease pathobiology led to the identification of an appropriate target population and predictive biomarker for mepolizumab treatment: patients with severe eosinophilic asthma and blood eosinophil count. Mepolizumab use provides clinically meaningful benefits in this target population, fulfilling an unmet need. This Clinical Commentary Review describes the clinical development of mepolizumab and details of how this program informed the development of other biologic therapies in patients with severe asthma. This account highlights how a personalized approach toward treatment of patients with severe eosinophilic asthma, supported by a large body of scientific evidence, ultimately led to new and effective treatments and improved patient outcomes.

Biologics for Severe Asthma: Treatment-Specific Effects Are Important in Choosing a Specific Agent

Patients with uncontrolled severe persistent asthma have greater morbidity, greater use of health care resources, and more impairment in health-related quality of life when compared with their peers with well-controlled disease. Fortunately, since the introduction of biological therapeutics, patients with severe eosinophilic asthma now have beneficial treatment options that they did not have just a few years ago. In addition to anti-IgE therapy for allergic asthma, 3 new biological therapeutics targeting IL-5 and 1 targeting IL-4 and IL-13 signaling have recently been approved by the Food and Drug Administration for the treatment of severe eosinophilic asthma, and approval of more biological therapeutics is on the horizon. These medications decrease the frequency of asthma exacerbations, improve lung function, reduce corticosteroid usage, and improve health-related quality of life. This article reviews the mechanisms of action, specific indications, benefits, and side effects of each of the approved biological therapies for asthma. Furthermore, this article reviews how a clinician could use specific patient characteristics to decide which biologic treatment may be optimal for a given patient.

Anti-IL-5 monoclonal antibodies for the treatment of asthma: an update

INTRODUCTION

Asthma exhibits marked heterogeneity in symptoms with severe or refractory asthma representing a clear area of unmet medical need. These patients require more specifically targeted treatments with monoclonal antibody-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5 and IL-13 having considerable potential as effective treatments for severe asthma. For the most part, anti-cytokine-based biologic therapies are more likely to give significant clinical benefit in carefully selected patient populations that take asthma phenotypes and endotypes into account.

AREAS COVERED

This review is based on recent English-language original articles in Pub Med or MedLine that reported significant clinical findings on the current status, therapeutic potential and safety of the anti-IL-5 biologics mepolizumab, reslizumab and benralizumab in the treatment of severe refractory asthma.

EXPERT OPINION

Anti-IL-5 treatment appears effective in patients with eosinophilic asthma through exacerbation prevention with accumulating evidence of glucocorticoid-sparing effects with an acceptable safety profile for these biologics.

Monoclonal Antibody Therapy in Childhood Asthma

PURPOSE OF REVIEW

There has been an explosion of monoclonal antibodies in the treatment of severe uncontrolled adult asthma. Studies have now been published in severe pediatric asthma. There are numerous questions that need to be answered in determining whether these modalities are appropriate and safe in children.

RECENT FINDINGS

This is a narrative review examining the latest pediatric literature on monoclonal antibodies, both approved and in the pipeline, for uncontrolled asthma. Presently, all of the biologics are positioned to treat patients with underlying type 2 high disease. Two monoclonal antibodies are approved for children 6 years of age and older, omalizumab and mepolizumab, with more likely approved in the near future. The effect of these agents in controlling severe pediatric asthma is promising. Data is limited to long-term efficacy and safety, and whether any agent has an effect on the natural history of asthma.

COVID-19, asthma, and biological therapies: What we need to know

Managing patients with severe asthma during the coronavirus pandemic and COVID-19 is a challenge. Authorities and physicians are still learning how COVID-19 affects people with underlying diseases, and severe asthma is not an exception. Unless relevant data emerge that change our understanding of the relative safety of medications indicated in patients with asthma during this pandemic, clinicians must follow the recommendations of current evidence-based guidelines for preventing loss of control and exacerbations. Also, with the absence of data that would indicate any potential harm, current advice is to continue the administration of biological therapies during the COVID-19 pandemic in patients with asthma for whom such therapies are clearly indicated and have been effective. For patients with severe asthma infected by SARS-CoV-2, the decision to maintain or postpone biological therapy until the patient recovers should be a case-by-case based decision supported by a multidisciplinary team. A registry of cases of COVID-19 in patients with severe asthma, including those treated with biologics, will help to address a clinical challenge in which we have more questions than answers.

Reducing the hidden burden of severe asthma: recognition and referrals from primary practice

Since their introduction many decades ago, systemic corticosteroids have become a mainstay treatment for asthma. Despite being a highly effective therapy, corticosteroids can cause significant adverse effects in patients. This results in a "double hit" for some patients as they suffer the burden of disease as well as the burden of treatment-induced morbidity.This article aims to raise awareness of the potential, harmful side effects of prolonged or repeated exposure to systemic corticosteroids in asthma. It also highlights the importance of referral of the appropriate patients with asthma from primary care for specialist assessment once other considerations such as adherence, inhaler technique and co-morbidity have been evaluated. We propose a simple decision step that may help busy primary care physicians and general practitioners to identify patients who could benefit from specialist assessment.Our decision step suggests that a patient with asthma should be reviewed at least once by an asthma specialist if he/she (i) has received ≥2 courses of oral corticosteroids in the previous year; asthma remains uncontrolled despite good adherence and inhaler technique; or (ii) has attended an emergency department or was hospitalized for asthma care.Such referral could facilitate wider access to diagnostic tools, in-depth assessment of confounding comorbidities, and non-corticosteroid-based therapies as needed, which may be unavailable in primary practice.

Hypersensitivity reactions to biologics (part I): allergy as an important differential diagnosis in complex immune-derived adverse events

Purpose

Biotechnological substances (BSs) are strongly relied upon to prevent rejection of transplanted organs, and to treat oncological, allergological, and other inflammatory diseases. Allergic reactions to partly foreign biologics can occur due to their potential immunogenicity. The severity of an immune response to a biological drug may range from no clinical significance to a severe, life-threatening anaphylactic reaction.

Methods

Detailed searches were performed on Pubmed, Web of Science, and Google Scholar to include all available publications. In addition, the Food and Drug Administration, the European Medicines Agency, and British Columbia Cancer Agency Drug Manual databases were screened for hypersensitivity reaction (HSR), infusion reaction, injection site reaction, urticaria, and anaphylaxis for individual BSs.

Results

Treatment with BSs can cause various types of HSR. These are mentioned in the literature with definitions such as allergic reactions, anaphylactoid reactions, anaphylaxis, HSR, infusion reactions, injection site reactions, cytokine release syndrome, and urticaria. Due to the overlap in signs and symptoms in the reported descriptions, it is not always possible to differentiate these reactions properly according to their pathomechanism. Similarly, many data reported as anaphylaxis actually describe severe anaphylactic reactions (grades III or IV).

Conclusion

There is an urgent need for a simpler symptom- or system-based classification and scoring system to create an awareness for HSRs to BSs. A better understanding of the pathophysiology of HSRs and increased clinical experience in the treatment of side effects will provide timely control of unexpected reactions. As a result, immunotherapy with BSs will become safer in the future.

Safety of Eosinophil-Depleting Therapy for Severe, Eosinophilic Asthma: Focus on Benralizumab

Eosinophils play a pivotal role in the inflammatory pathology of asthma and have been the target of new biologic treatments for patients with eosinophilic asthma. Given the central role of interleukin (IL)-5 in the eosinophil lifecycle, several therapies directed against the IL-5 pathway have been developed, including the anti-IL-5 antibodies mepolizumab and reslizumab and the IL-5 receptor α (IL-5Rα)-directed cytolytic antibody benralizumab. Eosinophil-depleting therapies represent a relatively new class of asthma treatment, and it is important to understand their long-term efficacy and safety. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that deplete eosinophils. However, evidence for these associations in humans is conflicting and largely indirect or based on mouse models. Substantial prospective clinical trial and postmarketing data have accrued, providing insight into the potential risks associated with eosinophil depletion. In this review, we explore the current safety profile of eosinophil-reducing therapies, with particular attention to the potential risks of malignancies and severe infections and a focus on benralizumab. Benralizumab is an IL-5Rα-directed cytolytic monoclonal antibody that targets and efficiently depletes blood and tissue eosinophils through antibody-dependent cell-mediated cytotoxicity. Benralizumab is intended to treat patients with severe, uncontrolled asthma with eosinophilic inflammation. The integrated analyses of benralizumab safety data from the phase III SIROCCO and CALIMA trials and subsequent BORA extension trial for patients with asthma, and the phase III GALATHEA and TERRANOVA trials for patients with chronic obstructive pulmonary disease, form the principal basis for this review.

Case of paradoxical adverse response to mepolizumab with mepolizumab-induced alopecia in severe eosinophilic asthma

Recent years have seen an increase in use of mepolizumab and other biological therapies for the treatment of severe eosinophilic asthma. A few cases of paradoxical responses to mepolizumab therapy have now been reported and are hypothesised as being a response to immune complex formation. We present a case of mepolizumab-induced alopecia in a patient with paradoxical adverse response to mepolizumab given for severe eosinophilic asthma. We postulate this could be secondary to autoimmune mechanisms and that it could help herald poor response to treatment, thereby facilitating early identification of patients having paradoxical responses.

Effect of fixed-dose subcutaneous reslizumab on asthma exacerbations in patients with severe uncontrolled asthma and corticosteroid sparing in patients with oral corticosteroid-dependent asthma: results from two phase 3, randomised, double-blind, placebo-controlled trials

BACKGROUND

Reslizumab 3 mg/kg administered intravenously is approved for the treatment of severe eosinophilic asthma. We assessed the safety and efficacy of subcutaneous reslizumab 110 mg in two trials in patients with uncontrolled severe asthma and increased blood eosinophils. The aim was to establish whether subcutaneous reslizumab 110 mg can reduce exacerbation rates in these patients (study 1) or reduce maintenance oral corticosteroid dose in patients with corticosteroid-dependent asthma (study 2).

METHODS

Both studies were randomised, double-blind, placebo-controlled, phase 3 studies. Entry criteria for study 1 were uncontrolled severe asthma, two or more asthma exacerbations in the previous year, a blood eosinophil count of 300 cells per μL or more (including no more than 30% patients with an eosinophil count <400 cells/μL), and at least a medium dose of inhaled corticosteroids with one or more additional asthma controllers. Patients in study 2 had severe asthma, a blood eosinophil count of 300 cells per μL or more, daily maintenance oral corticosteroid (prednisone 5-40 mg, or equivalent), and high-dose inhaled corticosteroids plus another controller. Patients were randomly assigned (1:1) to subcutaneous reslizumab (110 mg) or placebo once every 4 weeks for 52 weeks in study 1 and 24 weeks in study 2. Patients and investigators were masked to treatment assignment. Primary efficacy outcomes were frequency of exacerbations during 52 weeks in study 1 and categorised percentage reduction in daily oral corticosteroid dose from baseline to weeks 20-24 in study 2. Primary efficacy analyses were by intention to treat, and safety analyses included all patients who received at least one dose of study treatment. These studies are registered with ClinicalTrials.gov, NCT02452190 (study 1) and NCT02501629 (study 2).

FINDINGS

Between Aug 12, 2015, and Jan 31, 2018, 468 patients in study 1 were randomly assigned to placebo (n=232) or subcutaneous reslizumab (n=236), and 177 in study 2 to placebo (n=89) or subcutaneous reslizumab (n=88). In study 1, we found no significant difference in the exacerbation rate between reslizumab and placebo in the intention-to-treat population (rate ratio 0·79, 95% CI 0·56-1·12; p=0·19). Subcutaneous reslizumab reduced exacerbation frequency compared with placebo in the subgroup of patients with blood eosinophil counts of 400 cells per μL or more (0·64, 95% CI 0·43-0·95). Greater reductions in annual exacerbation risk (p=0·0035) and longer time to first exacerbation were observed for patients with higher trough serum reslizumab concentrations. In study 2, we found no difference between placebo and fixed-dose subcutaneous reslizumab in categorised percentage reduction in daily oral corticosteroid dose (odds ratio for a lower category of oral corticosteroid use in the reslizumab group vs the placebo group, 1·23, 95% CI 0·70-2·16; p=0·47). The frequency of adverse events and serious adverse events with reslizumab were similar to those with placebo in both studies.

INTERPRETATION

Fixed-dose (110 mg) subcutaneous reslizumab was not effective in reducing exacerbation frequency in patients with uncontrolled asthma and increased blood eosinophils (≥300 cells/μL), or in reducing the daily maintenance oral corticosteroid dose in patients with oral corticosteroid-dependent severe eosinophilic asthma. Higher exposures than those observed with 110 mg subcutaneous reslizumab are required to achieve maximal efficacy.

FUNDING

Teva Branded Pharmaceutical Products R&D.

Hypersensitivity and adverse reactions to biologics for asthma and allergic diseases

Introduction: The development of new biologic agents has provided definite therapeutic advances but, like with any new medications, safety remains a concern.Areas covered: Using PubMed, we reviewed the literature on the adverse effects (AE) to five biologics approved for asthma and/or allergic diseases: one anti-IgE (omalizumab), three anti-IL5 (mepolizumab, reslizumab, benralizumab), and one anti-IL4 (dupilumab).Expert opinion: Biologic agents approved for asthma and allergic diseases are generally safe. Most common AE are benign and tolerated, though long-term safety is lacking for most of them. A slightly increased risk of anaphylaxis to omalizumab and reslizumab required the inclusion of a black box warning, informing the patient, the need for post-injection observation period, and the provision of epinephrine autoinjectors for self-administration when needed. Hypersensitivity reactions, mainly urticaria and very rarely serum sickness have occurred.

Biologics for Asthma and Risk of Infection: Cause for Concern?

Monoclonal antibodies block specific inflammatory pathways involved in the pathogenesis of asthma. These pathways are important in host defense against pathogens, and in particular, against parasites. Despite theoretical concerns about infection risk, biologics seem to have a favorable safety profile. Data from large clinical trials and postmarketing surveillance for these drugs have not shown increases in severe infections, including those from parasitic organisms. This may be due to redundancy of effector cells within the immune system. Certain drugs have special considerations and precautions, and therefore, the prescribing physician should be familiar with product recommendations and warnings.

Asthma biologics: Comparing trial designs, patient cohorts and study results

OBJECTIVE

Five biologic therapies have FDA-approved indications for difficult-to-control asthma. The clinical trials that proved the efficacy and safety of these biologics were often similar in their inclusion criteria, study designs, and endpoints. Many of these trials have been reanalyzed post hoc to identify subsets of subjects considered to be enhanced responders. As a result, keeping up with the literature and deciding on the most appropriate biologic for our patients has become increasingly difficult. This review summarizes and compares trial designs, patient cohorts, and study results of the major trials involving these therapies.

DATA SOURCES

Included are basic science articles, online Food and Drug Administration (FDA) applications, and all the published reports of phase II and phase III clinical trials for FDA-approved asthma biologics.

STUDY SELECTIONS

Included are the major phase II and phase III clinical trials of 5 asthma biologics.

RESULTS

Because of variations in inclusion criteria and natural variations in enrolled cohorts, the baseline clinical traits and severity of study populations in asthma biologic trials differed significantly, which is important because baseline annualized exacerbation rates and blood eosinophilia are both strong predictors of a biologic's success. Notwithstanding, the trial results, when considered together, can help guide care providers in choosing the most appropriate biologic for our patients.

CONCLUSION

Understanding the details and differences in asthma biologic trial designs, patient cohorts, and in study results will help care providers make more informed decisions when choosing a biologic. We are hopeful this review will serve as a reference to care providers for this purpose.

Evaluation and Management of Difficult-to-Treat and Severe Asthma: An Expert Opinion From the Korean Academy of Asthma, Allergy and Clinical Immunology, the Working Group on Severe Asthma

Severe asthma (SA) presents in about 3%-5% of adult asthmatics and is responsible for over 60% of asthma-related medical expenses, posing a heavy socioeconomic burden. However, to date, a precise definition of or clear diagnostic criteria for SA have not been established, and therefore, it has been challenging for clinicians to diagnose and treat this disease. Currently, novel biologics targeting several molecules, such as immunoglobulin E, interleukin (IL)5, and IL4/IL13, have emerged, and many new drugs are under development. These have brought a paradigm shift in understanding the mechanism of SA and have also provided new treatment options. However, we need to agree on a precise definition of and its diagnostic criteria for SA. Additionally, it is necessary to explain the diagnostic criteria and to summarize current standard and additional treatment options. This review is an experts' opinion on SA from the Korean Academy of Asthma, Allergy, and Clinical Immunology, the Working Group on Severe Asthma, and aims to provide a definition of and diagnostic criteria for SA, and propose future direction for SA diagnosis and management in Korea.

Anti-IL-5 Biologicals Targeting Severe Late Onset Eosinophilic Asthma

Improved knowledge about the pathogenesis of asthma has facilitated the development of novel drugs and provided hope for patients with severe asthma. After the short- and long-term success of omalizumab in severe allergic phenotype, researchers have targeted patients with severe eosinophilic asthma who comprise up to 45% of adult severe asthma. Interleukin (IL)-5 and IL-5 receptor subunit α play crucial roles in the development, maturation, and operation of eosinophils. Currently, patients treated with anti-IL-5 biologicals depleting eosinophils experience the positive efficacy of these drugs, especially with regard to the reduction of exacerbation rate. The aim of this review was to shed light on severe eosinophilic asthma treatment with these new currently available agents selectively targeting IL-5 or its receptor, discussing their usage including pre-treatment concerns, such as selecting the target population and choosing the right agent among them, and subsequent assessment of relevant effect and safety issues.

Biologics in Children with Allergic Diseases

The prevalence of allergic diseases has been remarkably increased in the last decades. The global health burden of these conditions is substantial, since patients may experience disability, anxiety and emotional distress, social restrictions, and reduced quality of life and productivity, in particular, in the most severe cases. Recent advances in understanding the pathophysiology of allergic disorders have allowed identifying novel therapeutic strategies for the treatment of severe and uncontrolled allergic diseases. Although most studies have been performed in allergic asthma, biological drugs targeting other allergic diseases such as chronic spontaneous urticaria, atopic dermatitis, and food allergy are showing promising results. In this review, the most recent evidence on biologic therapies for allergic diseases, focusing on the pediatric age has been presented.

Severe Asthma and Biological Therapy: When, Which, and for Whom

Asthma is a heterogeneous chronic inflammatory disease of the airways that affects approximately 300 million people worldwide. About 5-10% of all asthmatics suffer from severe or uncontrolled asthma, associated with increased mortality and hospitalization, reduced quality of life, and increased health care costs. In recent years, new treatments have become available, and different asthma phenotypes characterized by specific biomarkers have been identified. Biological drugs are currently indicated for patients with severe asthma that is not controlled with recommended treatments. They are mostly directed against inflammatory molecules of the type 2 inflammatory pathway and are effective at reducing exacerbations, maintaining control over asthma symptoms, and reducing systemic steroid use, which is associated with well-known adverse events. Although biological drugs for severe asthma have had a major impact on the management of the disease, there is still a need for head-to-head comparison studies of biologics and to identify new biomarkers for asthma diagnosis, prognosis, and response to treatment. Identifying novel biomarkers could facilitate the development of therapeutic strategies that are precisely tailored to each patient's requirements.

The effectiveness of Reslizumab in severe asthma treatment: a real-world experience

Background

Increased numbers of blood and sputum eosinophils are associated with higher exacerbation frequency and increased asthma severity. In clinical trials, targeting Interleukin-5 has been shown to be a useful therapeutic strategy for patients with severe eosinophilic asthma.

Methods

Twenty-six patients have been commenced on Reslizumab in our institution since early 2017. Safety and clinical efficacy parameters were recorded at regular intervals.

Results

Mean ACQ-6 score at the start of treatment was 3.5. The average number of exacerbations in the year preceding treatment was 8.3 per person. 30% of patients had been admitted to hospital at least once over the 12 months preceding therapy. 54% of our patients were on long term oral steroid.

Our data showed sustained improvement of Asthma control (Mean improvement in ACQ-6 was 1.7 at 1 year, and 2.0 at 2 years, P = 0.0001). Of the patients who were on long term systemic steroids, 35.7% discontinued steroids completely, with a mean reduction of prednisolone dose of 5.2 mg at 1 year. There was a 79% reduction in the annual exacerbation frequency at 1 year, and 88% at 2 years (P = < 0.0001). Modest, albeit statistically significant increases in creatine kinase which seemed to plateau by 1 year were noted.

Conclusions

Overall, Reslizumab was well tolerated with discontinuation of treatment due to side effects recorded in only one patient. Our data confirm the utility of anti-IL5 therapy in a carefully selected phenotype of severe asthma with evidence of eosinophilic airway inflammation.

A drug safety review of treating eosinophilic asthma with monoclonal antibodies

Introduction: The last two decades have seen significant progress in the treatment of severe asthma especially the severe eosinophilic phenotype. This review article serves to update the reader on the known safety profiles of these medications. It does not serve as a review of their clinical efficacies.Areas covered: All four of the currently approved monoclonal antibodies (biologics) used in the treatment of severe asthma are discussed with reference to the known safety data garnered from clinical trials and real world evidence. A fifth, approved by The European Commission and FDA, but not yet by NICE or Health Canada, is also discussed.Expert opinion: For each of the five biologics the authors shall summarize the known safety profiles and also the potential adverse effects as their usage is extended long term with suggestions for real world studies to help us develop our knowledge base.

Efficacy and safety of mepolizumab in a real-world cohort of patients with severe eosinophilic asthma

BACKGROUND

The interleukin 5 (IL-5) pathway is an important component in the pathophysiology of severe eosinophilic asthma. Mepolizumab is a monoclonal antibody that targets the IL-5 pathway. Clinical trials showed efficacy of Mepolizumab in patients with severe eosinophilic asthma. However, reports on experience with treatment in a real-world cohort are limited.

OBJECTIVES

Evaluation of the efficacy and safety of Mepolizumab for treatment of severe eosinophilic asthma in a real-world cohort of patients.

METHODS

A clinical prospective observational trial included all patients >18 years treated with Mepolizumab between March 2016 to March 2019 at Rabin Medical Center. The composite primary outcome measures evaluated: increase in FEV1 by≥ 200 ml and/or decrease in exacerbation rate of ≥50% and/or cessation of oral corticosteroids (OCS) treatment or ≥50% decrease in dosage. Also evaluated: blood eosinophil count, adverse events and quality of life.

RESULTS

Of 61 patients, 50 (82.0%) achieved the primary outcome. The number of patients who suffered from frequent exacerbations decreased from 52 (85.2%) to 8 (13.1%) (p < 0.001). Twenty-two patients (68%) stopped OCS treatment or received >50% reduced dosage (p < 0.001). Mean FEV1 increased from 1.72 ± 0.78 liters to 1.87 ± 0.85 liters (p = 0.043). Response to therapy was seen within six months. Forty-nine patients (80%) reported an improvement in quality of life (p < 0.001). Only minor adverse events were reported.

CONCLUSION

Treatment with mepolizumab was well tolerated and significantly lowered the exacerbation rate and OCS dependence in a real-world cohort of severe eosinophilic asthma patients. Response to therapy was within six months and treatment effect was sustained over time.

Options of immunotherapeutic treatments for children with asthma

Introduction: Asthma is the most common chronic disease in children. Avoiding triggers, and pharmacologic treatment with short acting beta-agonist, inhaler corticosteroids and anti-leukotriene are often enough to obtain symptoms control. Nevertheless, there is a subset of children with severe asthma and poor symptom control despite maximal therapy. In these patients, anti-IgE and anti-IL5 monoclonal antibodies are suggested as the fifth step of Global Initiative for Asthma guidelines. Area covered: Immunotherapeutic treatments are now suggested for asthma management. This article will discuss the available evidence on allergen immunotherapy and biologic drugs in pediatric asthma treatment. Expert opinion: Previously published studies demonstrated a good efficacy and safety profile of Allergen Immunotherapy in patients with mild-moderate asthma and sensitization to one main allergen. New understanding of mechanisms underlying severe asthma inflammation has allowed the identifications of specific biomarkers guiding the clinician in the choice of patient specific drug. Among the suggested immunotherapeutic options, omalizumab (blocking IgE) remains the first choice for atopic 'early onset' asthma in patients aged over 6 years. Instead, mepolizumab (blocking the IL5 ligand) should be considered for 'eosinophilic' asthma. Other biologic drugs are under consideration but data on the pediatric population are still lacking.

Safety of Reslizumab in Uncontrolled Asthma with Eosinophilia: A Pooled Analysis from 6 Trials

BACKGROUND

Intravenous reslizumab, a monoclonal IL-5 antibody, is approved for treating severe asthma with eosinophilia. Limited structured information is available on the safety of reslizumab in larger populations.

OBJECTIVE

To investigate the safety profile of intravenous reslizumab 3.0 mg/kg by analyzing data from 6 asthma clinical trials: 5 placebo-controlled (duration ≤52 weeks) and 1 open-label extension (up to 2 years of treatment).

METHODS

Patients were aged 12 to 75 years with inadequately controlled asthma with eosinophilia. In the placebo-controlled trials, 730 patients received placebo and 1028 received reslizumab 3.0 mg/kg.

RESULTS

Adverse events (AEs) and serious AEs occurred in higher percentages of patients in the placebo group (81% and 9%) than in the reslizumab group (67% and 6%). Asthma, nasopharyngitis, and upper respiratory tract infection were the most common AEs with placebo and reslizumab. Three cases of anaphylaxis, related to reslizumab, were successfully managed with standard therapies. No significant difference in the incidence of malignancies was seen when compared with placebo or the general population. Among 756 patients with more than 12 months of reslizumab exposure, the AE rate was lower than in the placebo-controlled trials (367.3 vs 433.9 events/100 patient-years). The incidence of AEs in patients on treatment for more than 12 months was no higher than in patients with shorter treatment durations.

CONCLUSIONS

This analysis confirms that treatment with intravenous reslizumab for more than 12 months is well tolerated in patients with asthma, with no evidence of rare safety events that were not detected in individual trials.

Monoclonal antibodies in type 2 asthma: a systematic review and network meta-analysis

Since novel treatments to target eosinophilic inflammation in Type 2 asthma are emerging, we aimed to evaluate and meta-analyze the efficacy of monoclonal antibodies to reduce exacerbation rate. PubMed and Web of Science were searched for phase II and phase III randomized clinical trials with monoclonal antibodies targeting key mediators of type 2-associated asthma. Thirty trials were selected involving biologics that target the IL-5 pathway, IL-13, the common IL-4 and IL-13 receptor, IL-9, IL-2 and TSLP. As no head-to-head trials were retrieved from literature, we performed an arm-based network meta-analysis to compare effects on exacerbation rate between the different treatments.

Mepolizumab, reslizumab and benralizumab significantly reduced the risk of exacerbations compared to placebo (by 47–52%, 50–60%, and 28–51% respectively). Reslizumab and benralizumab also improved lung function. Dupilumab and tezepelumab improved lung function in frequent exacerbators. Lebrikizumab had no significant effect on the number of exacerbations, symptom control or health-related quality of life. Tralokinumab improved lung function compared to placebo. Network meta-analysis of all treatment and placebo arms, showed no superiority of one biologic over the others. Large reductions in exacerbation rates were observed compared to placebo, though only benralizumab was sufficiently powered (n = 2051) to demonstrate significantly decreased exacerbation rates in the subgroup analysis of IL-5 acting agents compared to placebo.

Monoclonal antibodies such as mepolizumab, reslizumab and benralizumab have proven their benefit to reduce exacerbation rates in severe persistent eosinophilic asthma in the published trials. However, no statistically significant superiority was observed of one biologic over the other in the network meta-analysis. More studies with direct head to head comparisons and better defined endotypes are required.

Targeted Therapy for Severe Asthma in Children and Adolescents: Current and Future Perspectives

Severe asthma in children remains a significant issue. It places a heavy burden on affected individuals and society as a whole in terms of high morbidity, mortality, consumption of healthcare resources, and side effects from high-dose corticosteroid therapy. New, targeted biologic therapies for asthma have emerged as effective add-on options, complementing our expanding understanding of asthma phenotypes/endotypes and the underlying immunopathology of the disease spectrum. They include omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab. Omalizumab represents the first available therapeutic option for allergic asthma in patients as young as 6 years of age. Its efficacy and safety have been established by several randomized controlled trials specifically conducted in pediatric patients, leading to its final registration > 10 years ago. Three new interleukin (IL)-5 targeted agents, mepolizumab, reslizumab, and benralizumab, have been approved for the treatment of severe eosinophilic asthma starting from 6 years of age, and varying by country. More recently, dupilumab, a targeted agent against the IL-4 receptor α-chain, was approved for patients ≥12 years of age in the United States after pivotal trials were completed. The late-stage clinical testing of these targeted agents has mostly involved patients aged 12 years and up, and the application of those data to younger children can be inappropriate and carry risk. The efficacy and safety of these newer biologics in children should be supported by adequate research within this targeted age group. In this review, we will present the most recent evidence on these five biological therapies for severe asthma and will discuss dosage and administration, their efficacy, safety, and future prospects, with a focus on the pediatric age group, defined as age < 18 years.

Targeting eosinophils: severe asthma and beyond

Recent research in the field of bronchial asthma has mainly focused on eosinophilic disease phenotype. Several trials proved the efficacy and safety profile of eosinophils and interleukin (IL)-5 targeting molecules, currently approved for severe asthma and available on the market. They include mepolizumab and reslizumab, IL-5 blocking molecules, and benralizumab, targeting the IL-5 receptor and eliciting a NK cell-mediated antibody-dependent cellular cytotoxicity against eosinophils. Eosinophilic inflammation represents the common pathophysiological background of several conditions, providing the rationale for the use of the same biologics beyond asthma. Although with different evidence grade, from clinical trials to case reports, anti-IL-5 biologics have been investigated in eosinophilic granulomatosis with polyangitis, allergic bronchopulmonary aspergillosis, chronic eosinophilic pneumonia, nasal polyposis, hypereosinophilic syndrome, and eosinophilic esophagitis. However, non-negligible differences between asthma and other eosinophilic diseases, particularly in eosinophils homing (blood and/or tissues), target organs and thus clinical features, probably account for the different response to the same drug in different clinical conditions and highlights the need for tailoring the therapeutic approach by modulating the drug dose and/or by combination therapy with multiple drugs. The optimal safety and tolerability profile of anti-IL-5 drugs warrants further and larger experimental and real-life investigations, which are needed especially in the field of non-asthma eosinophilic diseases. This review aims at summarizing the rationale for the use of biologics in eosinophilic diseases and their mechanisms of action. The current efficacy and safety evidence about eosinophils and IL-5 targeting molecules in asthma and in eosinophilic conditions beyond bronchi is also discussed.

Primary care of asthma: new options for severe eosinophilic asthma

Objective: Asthma is a common heterogeneous disease characterized by airway inflammation and bronchoconstriction. Current treatment guidelines provide recommendations for categorizing disease severity, asthma control and management. This paper reviews asthma assessment in primary care and describes the pathophysiology, clinical characteristics and new targeted treatments available for patients with severe eosinophilic asthma. Methods: A non-systematic PubMed literature search was conducted and articles, primarily from the last 5 years, were selected based on relevance to primary care practice, asthma pathophysiology and biologic therapies. Results: Despite optimal therapy including high-dose inhaled corticosteroids (ICS), long-acting β2-agonists and tiotropium, ∼4-10% of all patients with severe asthma continue to have poor asthma control. These patients have impaired quality of life, frequent exacerbations and are exposed to the side effects of repeated courses of oral steroids. Approximately 50% of patients with severe uncontrolled asthma have eosinophilic asthma, with increased airway expression of type 2 cytokines IL-4, IL-5 and IL-13. Eosinophilic asthma is identified in primary care by having eosinophils ≥150-300 cells/μL on a complete blood count with differential. Conclusions: A new class of agents is available for patients with moderate to severe eosinophilic asthma. Four biologic therapies - mepolizumab, reslizumab, benralizumab and dupilumab - that interfere with the regulation and activity of eosinophils have been approved by the FDA for patients with moderate to severe asthma with an eosinophilic phenotype. Primary care physicians should be familiar with these medications to explain part of the rationale for referral to specialist care and manage patient expectations for treatment.

[Update in severe asthma physiopathology and treatments]

Asthma is an inflammatory airway disease which presentation is highly heterogeneous. Last two decades provided new clinical and basic data concerning asthma physiopathology that make global understanding much complex. Phenotypes based on clinical settings and paraclinical investigations from large cohorts confirm old paradigm (eosinophilic vs. non-eosinophilic asthma) but also introduce new concepts (obesity-related asthma, late onset asthma, etc.). Conversely, improvement of big data analytics allows to initiate new cohorts aiming at better understanding the pathophysiology underlying those phenotypes and unraveling new ones. However, clinical and therapeutic impacts of those big data need to be further detailed. In parallel, biotherapies and innovative techniques as bronchial thermoplasty become available for severe asthmatic patients who did not respond to specific treatment in the past. Development of a personalized medicine in severe asthma becomes an important challenge for tomorrow. This review will focus on new pathophysiological concepts arisen from large cohorts and new therapeutic strategies available and in progress for severe asthma.

Efficacy and steroid-sparing effect of benralizumab: has it an advantage over its competitors?

Severe refractory asthma is characterized by a higher risk of asthma-related symptoms, morbidities, and exacerbations. This disease also determines much greater healthcare costs and deterioration in health-related quality of life (HR-QoL). Another concern, which is currently much discussed, is the high percentage of patients needing regular use of oral corticosteroids (OCS), which can lead to several systemic side effects. Airway eosinophilia is present in the majority of asthmatic patients, and elevated levels of blood and sputum eosinophils are associated with worse control of asthma. Regarding severe refractory eosinophilic asthma, interleukin-5 (IL-5) plays a fundamental role in the inflammatory response, due to the profound effect on eosinophils biology. The advent of the biological therapies provided an effective strategy, even if the increased number of molecules with different targets raised the challenge of choosing the right therapy and avoid overlapping. When considering severe refractory eosinophilic asthma and anti-IL-5 treatments, it is not easy to define which drug to choose between mepolizumab, reslizumab, and benralizumab.

In this article, we carried out an indirect comparison among literature data, especially between OCS reduction studies (ZONDA-SIRIUS) and pivotal studies (SIROCCO-MENSA), evaluating whether the clinical efficacy and the steroid-sparing effect of benralizumab may represent an advantage over other compounds. This data could help the clinician in the decision process of treatment choice, within the different available therapeutic options for eosinophilic refractory severe asthma.

Endotypes in allergic diseases

PURPOSE OF REVIEW

The precision medicine concept is both appealing and challenging. We review here the recent findings in the endotype-driven approach for major allergic diseases.

RECENT FINDINGS

Stratified medicine for different allergic diseases can identify patients who are more likely to benefit or experience an adverse reaction in response to a given therapy and anticipate their long-term outcome and vital risk. In addition, this approach potentially facilitates drug development and prevention strategies.

SUMMARY

The endotype-driven approach in allergic diseases has tremendous potential, but there are notable barriers in reaching the new world of precision medicine. Multidimensional endotyping integrating visible properties with multiple biomarkers is recommended for both type 2 and nontype 2 allergic diseases to provide evidence that a certain pathway is the key driver for a given patient. Significant healthcare system changes are required to achieve the expected targets.

A review of dupilumab in the treatment of atopic diseases

Dupilumab is a fully human monoclonal IgG4 antibody directed against the alpha subunit of the IL-4 receptor and prevents the signaling of IL-4 and IL-13, two type 2 cytokines known to be important drivers of atopic diseases. In March of 2017, the United States Food and Drug Administration (FDA) approved dupilumab for the treatment of moderate-to-severe atopic dermatitis in adults that is uncontrolled with topical medications, becoming the first biologic agent approved to treat this chronic skin condition. In October of 2018, Dupilumab received approval by the FDA as an add-on maintenance therapy in patients with moderate-to-severe asthma aged 12 years or older with an eosinophilic phenotype or with oral corticosteroid-dependent asthma. This review summarizes the characteristics of dupilumab and the clinical research that has been published to date, including treatment efficacy and adverse events.

The use of biologics for immune modulation in allergic disease

The rising prevalence of allergies represents an increasing socioeconomic burden. A detailed understanding of the immunological mechanisms that underlie the development of allergic disease, as well as the processes that drive immune tolerance to allergens, will be instrumental in designing therapeutic strategies to treat and prevent allergic disease. Improved characterization of individual patients through the use of specific biomarkers and improved definitions of disease endotypes are paving the way for the use of targeted therapeutic approaches for personalized treatment. Allergen-specific immunotherapy and biologic therapies that target key molecules driving the Th2 response are already used in the clinic, and a wave of novel drug candidates are under development. In-depth analysis of the cells and tissues of patients treated with such targeted interventions provides a wealth of information on the mechanisms that drive allergies and tolerance to allergens. Here, we aim to deliver an overview of the current state of specific inhibitors used in the treatment of allergy, with a particular focus on asthma and atopic dermatitis, and provide insights into the roles of these molecules in immunological mechanisms of allergic disease.

Severe refractory asthma: current treatment options and ongoing research

Patients with severe asthma have a greater risk of asthma-related symptoms, morbidities, and exacerbations. Moreover, healthcare costs of patients with severe refractory asthma are at least 80% higher than those with stable asthma, mainly because of a higher use of healthcare resources and chronic side effects of oral corticosteroids (OCS). The advent of new promising biologicals provides a unique therapeutic option that could achieve asthma control without OCS. However, the increasing number of available molecules poses a new challenge: the identification and selection of the most appropriate treatment. Thanks to a better understanding of the basic mechanisms of the disease and the use of predictive biomarkers, especially regarding the Th2-high endotype, it is now easier than before to tailor therapy and guide clinicians toward the most suitable therapeutic choice, thus reducing the number of uncontrolled patients and therapeutic failures. In this review, we will discuss the different biological options available for the treatment of severe refractory asthma, their mechanism of action, and the overlapping aspects of their usage in clinical practice. The availability of new molecules, specific for different molecular targets, is a key topic, especially when considering that the same targets are sometimes part of the same phenotype. The aim of this review is to help clarify these doubts, which may facilitate the clinical decision-making process and the achievement of the best possible outcomes.

Anti-interleukin (IL)-5 as a steroid-sparing agent in chronic eosinophilic pneumonia

Introduction: Anti-interleukin (IL)-5 therapy is a novel drug class clinically effective in patients with diverse eosinophil-related disorders such as allergic eosinophilic asthma, eosinophilic granulomatosis with polyangiitis (EGPA), nasal polyposis, eosinophilic COPD, and other non-pulmonary disorders such as eosinophilic esophagitis. Chronic eosinophilic pneumonia (CEP) is a steroid responsive disorder, however, relapses are common following corticosteroid tapering. Case Study: We present the case of a 42-year-old woman with steroid-dependent relapsing CEP successfully treated with anti-IL-5 antibody. Results: Treatment with anti-IL-5 antibody resulted in remission with the ability to taper off the steroids, and no recurrence of the disease for 6 months. Conclusion: Our case report supports the potential use of anti-IL-5 therapy for remission of patients with CEP with recurrent relapses. Whether, it would also be an effective initial therapy might also be an area that deserves future investigation.

Assessment of the long-term safety of mepolizumab and durability of clinical response in patients with severe eosinophilic asthma

BACKGROUND

Mepolizumab has demonstrated favorable safety and efficacy profiles in placebo-controlled trials of 12 months' duration or less; however, long-term data are lacking.

OBJECTIVE

We sought to evaluate the long-term safety and efficacy of mepolizumab in patients with severe eosinophilic asthma (SEA).

METHODS

COLUMBA (Open-label Long Term Extension Safety Study of Mepolizumab in Asthmatic Subjects, NCT01691859) was an open-label extension study in patients with SEA previously enrolled in DREAM (Dose Ranging Efficacy And Safety With Mepolizumab in Severe Asthma, NCT01000506). Patients received 100 mg of subcutaneous mepolizumab every 4 weeks plus standard of care until a protocol-defined stopping criterion was met. Safety end points included frequency of adverse events (AEs), serious AEs, and AEs of special interest. Efficacy end points included annualized exacerbation rates, changes from baseline in Asthma Control Questionnaire 5 scores, and blood eosinophil counts. Immunogenicity was also assessed.

RESULTS

Overall, 347 patients were enrolled for an average of 3.5 years (maximum, 4.5 years; total exposure, 1201 patient-years). On-treatment AEs were reported in 94% of patients (exposure-adjusted rate, 3688 events/1000 patient-years). The most frequently reported on-treatment AEs were respiratory tract infection, headache, bronchitis, and asthma worsening. Seventy-nine (23%) patients experienced 1 or more on-treatment serious AEs; there were 6 deaths, none of which were assessed as related to mepolizumab. For patients with 156 weeks or greater enrollment, the exacerbation rate was 0.74 events/y (weeks 0-156), a 56% reduction from the off-treatment period between DREAM and COLUMBA. For all patients, at the first postbaseline assessment, the mean Asthma Control Questionnaire 5 score was reduced by 0.47 points, and blood eosinophil counts were reduced by 78%, with similar improvements maintained throughout the study. The immunogenicity profile (8% anti-drug antibodies) was consistent with previous studies.

CONCLUSION

These data support the long-term safety and efficacy of mepolizumab in patients with SEA.

Benralizumab, an add-on treatment for severe eosinophilic asthma: evaluation of exacerbations, emergency department visits, lung function, and oral corticosteroid use

There are now multiple monoclonal antibodies targeting different inflammatory pathways of severe asthma. Benralizumab is a recently approved monoclonal antibody indicated for the treatment of severe eosinophilic asthma by targeting a subunit of the IL-5 receptor. Treatment with benralizumab results in significant reductions of blood and tissue eosinophils. Early studies report that this therapy has an adequate safety profile, and this was confirmed in later trials. Phase III studies have shown that benralizumab is effective in reducing the rate of exacerbations and improving asthma symptoms and quality of life in patients with severe eosinophilic asthma. Additionally, treatment with benralizumab has resulted in important reductions in the use of chronic oral corticosteroids. In this review, we evaluate the evidence up to date on the efficacy of benralizumab in severe eosinophilic asthma and explore the implications of this therapy in the ever-growing landscape of therapies for severe asthma.

Recent developments in the use of biologics targeting IL-5, IL-4, or IL-13 in severe refractory asthma

INTRODUCTION

Severe or refractory asthma is seen in approximately 5% of asthmatic subjects who have unsatisfactory symptom control despite adherence to high-dose inhaled glucocorticoid therapies resulting in significant morbidity, reduced quality of life and health-care cost implications. Asthma exhibits marked heterogeneity both clinically and at the molecular phenotypic level requiring specifically targeted treatments to block the key pathways of the disease. Monoclonal antibody-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5, and IL-13 have considerable potential as effective treatments for severe asthma. Areas covered: This review is based on recent English-language original articles in PubMed or Medline that reported significant clinical findings on the current status, therapeutic potential, and safety of biologics targeted at IL-4, IL-5, and IL-13 in the treatment of asthma together with the potential utility of simple reproducible non-invasive biomarkers to guide the effective use of biologic-based therapy that do not require direct sampling of the airways Expert commentary: The further development of reproducible and straightforward discriminatory non-invasive biomarkers may aid identification of those patients most likely to benefit from treatment with these interventions.

Tetrahydrocurcumin, a major metabolite of curcumin, ameliorates allergic airway inflammation by attenuating Th2 response and suppressing the IL-4Rα-Jak1-STAT6 and Jagged1/Jagged2 -Notch1/Notch2 pathways in asthmatic mice

BACKGROUND

Curcumin (Cur), derived from Curcuma species, exhibits anti-inflammatory, antioxidant, and anticancer effects. Although Cur has some beneficial effects on asthma, its clinical application is limited by its low bioavailability. Tetrahydrocurcumin (THC), the major active metabolite of Cur, has multiple biological functions, similarly to Cur, and importantly, it showed enhanced bioavailability in tissues and plasma. However, the effect of THC on asthma has not been reported.

OBJECTIVE

The current study sought to investigate the efficacy of dietary THC on allergic asthma compared to that of Cur in an animal model.

METHODS

The anti-inflammatory effects of Cur and THC were evaluated in an ovalbumin-induced asthmatic mouse model. The nasal symptoms, pathological alterations of the lung tissues, oxidants and antioxidants, cytokine production, T cell subsets, and Th2-related signalling pathway activity were assessed.

RESULTS

Both THC and Cur had beneficial effects on asthmatic mice with regard to nasal symptoms, pathological changes (eosinophils and mucus hyper-production), oxidative stress (malondialdehyde), cytokine production (IL-13), Th17 and cytotoxic T cell subsets, and Th2 signalling pathway (IL-4Rα-Jak1-STAT6 and Jagged1/Jagged2-Notch1/Notch2 axis) activity. THC was more effective than Cur in suppressing tissue eosinophilia, mucus production, and IL-4Rα/Jak1/STAT6 pathway activity. Furthermore, only THC inhibited peripheral eosinophil levels, Th2 cytokines (IL-4 and IL-5), and Th2 cell subsets and enhanced an antioxidant enzyme (glutathione).

CONCLUSION AND CLINICAL RELEVANCE

The above results demonstrated for the first time that THC was superior to Cur in modulating allergic asthmatic phenotypes, especially attenuating the Th2 response. THC might be a potentially effective agent for asthma treatment.

A Review of Three New Anti-interleukin-5 Monoclonal Antibody Therapies for Severe Asthma

Asthma is a chronic respiratory condition that is characterized by reversible airflow obstruction. Interleukin-5 (IL-5) is involved in the pathophysiology of the disease and drugs targeting IL-5 have been studied for years as a possible treatment option for severe asthma. In this review, the authors searched PubMed for major drug therapies and clinical trials against IL-5. A total of 29 articles met the criteria for selection and were shortlisted; of these, 10 papers were on benralizumab, 14 on mepolizumab, and five on reslizumab. The three drugs proved to be safe and efficacious for patients with severe asthma, leading to decreased rates of asthma exacerbations, lowered levels of eosinophils, and improved pulmonary functions in various studies. Patients also reported an improvement in the quality of life. The side effects of these three drugs were mild and no deaths directly linked to the drug were reported. However, longer duration studies are required to draw firm and strong conclusions on the safety of these therapeutic agents.

Biological therapies for eosinophilic asthma

INTRODUCTION

Severe uncontrolled asthma is by definition refractory to traditional therapies or can be controlled only with therapies that have intolerable side effects. Monoclonal antibodies that target interleukin (IL)-5/IL-5Rα, IgE, and IL-4Rα have shown favorable results in clinical trials, including reductions in asthma exacerbations and other important clinical outcomes. These biological agents offer treatment alternatives to patients with uncontrolled severe eosinophilic asthma.

AREAS COVERED

This article reviews how the shifting emphasis toward identifying distinct asthma phenotypes has led to the approval of biological therapies that preferentially benefit patients with severe eosinophilic asthma. The clinical trials that led to the approval of these biologic treatments are discussed in detail.

EXPERT OPINION

Biologic therapies targeting the IL-5, IgE, IL-4/IL-13 signaling pathways have been successful in clinical trials in subjects with severe eosinophilic asthma. Some of these agents have also been successful regardless of peripheral blood eosinophil counts. These treatments have shown a relatively favorable safety profile in clinical trials, although long-term safety data for some of these agents are limited. Due to the high costs associated with these medications, they should be reserved for select patients where they yield a therapeutic and pharmacoeconomic advantage.

Diagnosis and Novel Approaches to the Treatment of Hypereosinophilic Syndromes

PURPOSE OF REVIEW

Hypereosinophilic syndrome (HES) is characterized by persistent hypereosinophilia associated with end-organ damage. As our understanding of the pathogenesis of various forms of HES broadens, so does our ability to tailor steroid-sparing therapies for each subtype. The purpose of this review is to summarize recent literature related to the etiology, diagnosis, and management of HES.

RECENT FINDINGS

Mutations involved in subsets of HES can guide the choice of tyrosine kinase inhibitors beyond just imatinib. Several biologics that target interleukin-5 or its receptor have shown beneficial and selective eosinophil-reducing effects in clinical trials for asthma and other disorders including HES. Early clinical data with emerging therapies such as dexpramipexole and anti-Siglec-8 antibody show promise, but need to be confirmed in randomized trials. Several new biologics and tyrosine kinase inhibitors have been shown to lower eosinophil numbers, but more randomized trials are needed to confirm efficacy in HES.

Reslizumab in the treatment of severe eosinophilic asthma: an update

A marked heterogeneity is exhibited by asthma both clinically and at the molecular level with different phenotypes driven by diverse mechanistic pathways that require specifically targeted treatments. Biologics aimed at IL-4/13, IL-5 or IgE are proven or potentially effective treatments for patients with difficult to treat eosinophilic asthma. Importantly, it is now widely accepted that biologic-based therapies give significant clinical improvements in those patient populations where asthma phenotypes are taken into account. Such asthma phenotypes have been identified by reproducible and straightforward discriminatory biomarkers. This short review discusses recent studies of the effectiveness of the anti-IL-5 reslizumab in relation to the use of simple reproducible biomarkers in eosinophilic asthma.

Safety of humanized monoclonal antibodies against IL-5 in asthma: focus on reslizumab

INTRODUCTION

Reslizumab, a humanized mAb against IL-5, reduces the number of eosinophils in the blood and lungs. Based on efficacy and safety data from pivotal RCTs, reslizumab had been approved for use as an add-on maintenance treatment of severe asthma with an eosinophilic phenotype in adults who have a history of exacerbations despite receiving their current asthma medicines. Areas covered: Current literature on reslizumab has been reviewed with a specific focus on its safety profile in the treatment of severe asthma. Expert opinion: Large pivotal and supportive trials reinforce the view that reslizumab is well tolerated, with an acceptable safety profile in patients exposed for longer than 2 years. However, no or few data concerning safety in special populations such as smokers, those with immune- and cellular senescence, patients with comorbidities and those receiving multi-drug treatments are available as yet. Furthermore, we need to fully elucidate some fundamental issues such as the risk of anaphylaxis and the long-term risk-benefit ratio of the impact of depletion of eosinophils and the potential risk of malignancies induced by a treatment with this anti-IL-5 agent.